(1) Field of the Invention
The present invention relates to a health care system that can protect confidentiality of health information of a user, such as a body weight and a blood pressure, when the health information is obtained from the user and received via a network, and a health care service including health advice is provided back to the user based on the health information.
(2) Description of the Related Art
In recent years, people have been increasingly concerned about health, and various measuring apparatuses have been sold and have become widespread. Such measuring apparatuses can be easily used for obtaining health information, such as a body weight, a blood pressure, and body composition in households. Furthermore, new health care services have emerged that perform health management instead of a user and provide feedback on health advice to the user (for example, see Non-patent reference 1: Ascii Media Works. (Mar. 8, 2007). “Tanita, nettowaaku wo riyoushita herusu kea saabisu ‘monitaringu yua herusu’ wo kaishi (Tanita launches healthcare service “Monitoring Your Health” using network)”. Retrieved on Oct. 11, 2007 from <http://ascii24.com/news/i/serv/article/2007/03/08/667,789-000. html>.
In such health care services, various measuring apparatuses transmit the obtained various health information to devices in a household, such as a personal computer (PC) and a special purpose terminal. Then, such devices in a household uniformly manage the transmitted various health information through accumulation of data. Furthermore, the devices transmit various health information to servers via networks on a regular basis. Then, the servers provide health care services that perform health management instead of a user and provide feedback on health advice to the user.
On the other hand, health information of a user is personal information to the user. Thus, when health information of a user is transmitted via wireless communication or via the Internet, measures for preventing third persons from tapping and leaking information need to be taken.
In general, in order to protect user's health information to be transmitted through a communication path, data is encrypted. In a system where devices in a household temporarily collect data of health information that has been obtained by various measuring apparatuses and transmit the collected data to a server via a network, each of the measuring apparatuses and the server share a key and each of the measuring apparatuses encrypts the obtained data using the key. The encrypted data is transmitted to the server through each of the devices in a household. Then, the data is decrypted by the server using the shared key. Since the data is decrypted thus never converted into plain text during the transmission, health information may not be disclosed through tapping and leaking of information.
However, conventionally, when the user use several health care services, the measuring apparatuses have a problem of increased processing load for encrypting data. For example, assume that the user uses 3 health services, and the system needs to transmit blood pressure information of the user to 3 different servers. Thus, a blood pressure meter needs to encrypt the obtained blood pressure data using respective keys for each of the servers. In other words, the blood pressure meter needs to encrypt data 3 times per measurement of a blood pressure. In other words, when the user uses N number of services that respectively need to transmit blood pressure information, the blood pressure meter needs to encrypt the information N number of times.
As described above, there is a problem that the more the number of services increases, the more an amount of processing increases in a measuring apparatus. In general, the measuring apparatuses are portable devices driven by batteries. In order to extend the battery life as long as possible, the amount of processing needs to be reduced as much as possible. Thus, the number of processing for encrypting a large amount of data needs to be reduced as much as possible. In other words, when manufactured, the measuring apparatuses may not support increased number of processing for encrypting data, along with the increased number of services.
The present invention has been conceived for solving such problems, and has an object of providing a health care system and others that can suppress an amount of processing for encrypting data, regardless of the number of services to be used by a user.